Fire an employee for the wrong reason — or in the wrong situation — and the employee could claim retaliation and file a lawsuit.

Several activities by employees are off-limits to retaliatory actions such as firing or disciplinary action. Any retaliation by the employer could spell potential legal trouble, such as a wrongful termination lawsuit.

In order to prevent illegal retaliation from occurring in your workplace, you have to understand some basic definitions:

Retaliation occurs when an employer takes an adverse action against a covered individual because he or she engaged in a protected activity.

An adverse action is taken to keep someone from opposing a discriminatory or harassing practice or participating in an employment discrimination proceeding. Examples of adverse actions include terminating an employee, denying a promotion and giving an unjustified negative performance evaluation.

For purposes of federal employment laws administered by the EEOC, covered individuals are people who have opposed unlawful practices, participated in proceedings, or requested accommodations related to employment discrimination based on race, color, sex, religion, national origin, age, or disability. Individuals who have a close association with someone who has engaged in protected activity are also covered. For example, it is illegal to terminate an employee because his employee-spouse participated in employment discrimination litigation. Note: In addition to the employment laws administered by the EEOC, retaliation can occur against individuals who may be protected by other federal, state, or local laws. This includes the federal Family Medical Leave Act and whistleblower laws that bring attention to ethical, financial, or other concerns

Protected activity includes opposing a practice believed to be unlawful discrimination. For example, an employee complaining about treatment he or she believes is discriminatory — directed at the employee or a co-worker. Protected activity also includes participation in an employment discrimination proceeding or requesting a reasonable accommodation based on religion or disability.